Method subset

core/src/main/java/io/ddf/content/ViewHandler.java:179–185

(List<Column> columnExpr, Expression filter)

  }

  @Override
  public DDF subset(List<Column> columnExpr, Expression filter) throws DDFException {
    DDF subset = _subset(columnExpr, filter);
    subset.getMetaDataHandler().copyFactor(this.getDDF(), this.getDDF().getColumnNames());
    return subset;

  }

  protected DDF _subset(List<Column> columnExpr, Expression filter) throws DDFException {
    updateVectorName(filter, this.getDDF());